Mining machine



Aug. 29, 1939.

L. E. MITCHELL MINING MACHINE Filed April 25, 1956 '7 Sheets-Shea?I A1 L, n E mm www. New @M Y E.

A TTY Aug. 2:9, 1939.

L, E. MITCHELL MINING MACHINE Filed April 25. 1936 '7 SheetsfSheet 2 {NMEA/Tore.' l Lvvl E. MlTGHiLL, BYZa/L.

Aug. 29, 1939.' L. E. MITCHELL 2,171,043

l MINING MACHINE Filed Ap`ri 1 25;, 19:56 7 sheets-sheet 4 LO f2 /M/f/voe; (sl/Q LEWIS E. MHCHELL.

A TTY Aug. 29, 1939. L. E. MITCHELL 2,171,043

MINING MACHINE Filed April 25, 19:563 '7 sheets-sheet 5 /A/Vf/Vro/.' L Ewls E. MlTcHELL, 5y

A Tfr Aug. 29, 1939. L. E. MITCHELL 2,171,043

.MINING MACHINE y l Filed April 25, 1936 7 Sheets-Sheet 6 Wb l 4o MAAS/Woe;

LEWIS E. MITCHELL,

DYMM.

Aug- 29, 1939- I. l H L. E. MITCHELL 2,171,043

MINING MACHINE' FiledApril 25, 193e 7 sheets-sheet 7 #WE/Woe;

LEWIS EMITQHELL, EY

Patented Aug. 29, 1939 .2,171,043l ivnNrNo MACHINE Lewis E. Mitchell,

Columbus, Ohio, assigner to- The Jeffrey Manufacturing Company, a corporation of Ohio Application April .25, 1936, serial No. '16,456

12 Claims.

This invention relates to a mining machine and more particularly to a mining to cut horizontal coal mine.

machine adapted kerfs at varying elevations in a An object of the invention is to provide a mining machine of the above mentioned type having a frame with a iiat bottom `adapted to rest directly on a mine floor and to slide thereover, which machine is provided with a horizontal kerf cutter which may be by to cut horizontal Another object of adjusted in elevation therekerfs at various heights. the invention is to provide a mining machine of the above mentioned type which has a minimum over-all height and a minimum over-all length whereby it may be employed in lo-w seam mines and may bey employed in a mine employing the conveyor system of mining in a room tion.

Another object extremely compa above mentioned is Flexible in that in elevation with and pillar type of mining operaof the invention is to provide an ct mining machine of the type yet to provide a machine which the cutter bar may be adjusted respect to the main frame.

A further object of the invention 1s the. provision of improved planetary gear driving a feeding shaft connected t0- ing machine.

mechanism for rope drum` on the axis of the the chain kerf -cutter of a min- Another object of the invention is the provision of an improved apron guard connected topa cutter bar and movable up and down therewith While overlapping the front end of the frame of a mining machine.

A further object of the invention is theprovision of improved connections on a mining machine for the free end of a feeding rope connected to mechanism for sliding the mining machine over the mine bottom cutter thereof is Another object of a plurality of while the top keriadjusted to various elevations. of the invention is the provision spaced-apart telescopic guiding devices connected between the cutter bar of a mining machine thereon, combine ing the elevation of a tained in driving and the supporting framework d with a lifting device for vary-V horizontal kerf -cutter mainconnection with motor operated mechanism of the main frame.

A further object of sion of improved rope the invention is the providrum feeding apparatus.

enclosed within the supporting frame but controlled by a single wheel above said frame to effect either haulage speed of the. machine or feeding movement thereof.

Other objects o i the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims. In the accompanying drawings,

Fig. 1 is a plan View of the mining machine rcomprising my invention with the cutter bar cut off to reduce the length of the drawing;

Fig. 2 is a side elevational view of the device of Fig. 1;

Fig. 3 is an elevational sectional view taken on the line 3-3 of Fig. the arrows;

1 looking in the direction of Fig. 4 is a. sectional plan view taken on the line l-ll of Fig. 3 looking in the arrows;

direction. of the Fig. 5 is a sectional elevational view taken on the line 5-5 of Fig. 1 looking in the direction of the arrows;

Fig. 6 is a sectional elevational View taken on the line 6-5 of Fig. 4 looking of the arrows;

Fig. 'l is a sectional the kmachine taken on in the direction plan view of a portion of the'line 'I-l of Fig. 6

looking in the direction of the arrows;

Fig. 8 is a sectional elevational viewtaken on the line 8-8 of the arrows;

Fig. 9 is a plan and sectional taken on the line 9-9 of Fig. .direction of the arrows;

Fig. lO'i's a sectional plan view Fig. 1 looking in the direction of View of la detail 3 looking in the of the planetary 'Igearmechanism taken on the line lll-lil of Fig.

l3 looking in the direction of the a'ITOWS Fig. 11 is a plan and sectional view taken on -the line ll-ll of Fig. 3 looking vof the arrows;

Y Fig.` 12 is a sectional view of the line 12-12 of Fig. 4 looking of the arrows; and

in the direction a detail taken on in the direction Fig. 13 is an end elevational view taken on the line l3|3 of Fig. 12 looking in the arrows. i

' The mining machine ally of the Shortwall ally employed in a relatively cutting horizontal kerfs across mine room. It is particularly c the direction of herein disclosed is genertype, that is, it is generwide room for the face of thel onstructed for a room and pillar type of mining system employing conveyors in which there will be which yruns parallel to the room a-face conveyor face and feeds a room conveyor which runs parallel to a rib of the room, said room conveyor veyors of the complete system mine cars.

feeding entry conwhich will load It is desirable .to keep the length of the main frame of the mining machine as short as possible to the end that the face conveyor may be maintained as close to the mine face as possible, whereby supporting timbers may be provided relatively close to the mine face. It is, of course, evident that both the face conveyor and the mining machine must work between the timbers and the mine face.

Referring particularly to Figs. 1 and 2 of the drawings it is to be seen that the mining machine comprises a main frame 26 to which is attached for vertical adjustment a kerf cutting mechanism 2 i. The main frame 20 is formed of two sections comprising the motor section 22 and the gearing section 23, which sections 22 and 23 are removably attached together as by nuts and bolts 24. By removing the nuts 24, 24, the motor section 22 may be entirely removed from the main frame 20.

The section 23 is welded to and carried upon a fiat bottom or skid pan 25 (Figs. 2 and 6), which is adapted to rest upon and slide over the oor of a mine room. The motor section 22 the bottom' of which is flush with the bottom of the pan 25 in direct contact with the mine bottom, comprises a housing within which is mounted an electric motor 25 provided with a rotating armature shaft 2l (Fig. 3) extending into the housing of the gearing section 23 on a horizontal longitudinal axis. To provide access tothe brushes of the motor 26, the housing of the motor section 22 is also provided with a pair of gas-tight removable caps 22, 28.

Rigidly attached to and forming a part of the motor section 22 is a control box 29 for the electric motor 25, which is provided with a removable gas-tight cap Si! to provide access to the controls therein. A control lever 32 and a reverse lever 3i are provided for controlling appropriate switches within the switch-box 29, for starting the motor 26 and for reversing its direction of rotation.

Adjacent the rear central portion oi' the motor section 22, is provided a detachable guide sheave 33, the details of which are illustrated in Fig. 5 and will be described more in detail hereinafter.

Also associated with the trailing side of the motor section 22, at that corner thereof remote from the working face of the mine vein, are mounted on the bottom plate 22', the guide rollers or pulleys 336 and 33? which may be alternately engaged by a retarding or guide rope or cable 34. The leading side of the motor section 22 as shown in Fig. 1 carries the cable guide rollersi and 39, the guide roller 38 being pivoted to a bracket fixed to the control box 29, while the guide roller 39 as shown in Fig. 2 is pivoted to brackets 4t, 'lil which in turn are pivotally connected as shown at 4i, 4| to brackets 4|', 4| secured to the motor control box 29. The guide roller 39 may be swung either to its full line'position shown in Fig. 1 or to the dotted line position. The electric cable E2 shown in Fig. l leads from a distant source of electric power supply to the control box 29, and motor starting resistance 43 may be located in the frame of the motor section 22 in the position illustrated in Fig. 1.

By referring to Fig. 5 it will be seen that the retarding rope drum mechanism 35 comprises a drum .14 journaled on the stationary stub bearing i5 secured rigidly to the vertical plate 46 of the motor section 22. Secured to the vertical plate l5 is a irusto-conical clutch element 41 in position to co-operate with the brake lining 48 carried by the clutch element or brake drum 49 which is rigidly attached to the inner flange of the drum 44. By shifting thedrum 44Ilongitudinally along the stub bearing 45, the retarding force effected by the cone clutch or brake may be effectually adjusted.

In order to shift the drum 44 to partially apply the slip clutch shown in Fig. 5, I provide a threaded rod 5G adapted to be received by the threaded bore El in the axial center of the stub bearing 35. and key a hand wheel 52 to the outer end of the rod 55. The Wheel 52has a hub 53 the inner side of which engages the anti-friction bearing 54 mounted within the cup 54 at the center of the outer ange of the rope drum 44. A collar 55 on the rod 50 is located within the drum and thereby cause movement of the clutch elements 47, 49 toward or away from each other,

The kerf-cutting mechanism 2i 56 mounted upon and rigidly attached to a cutter bar support o-r head 5l. The kerf-cutting mechanism is adjustable along vertical lines with respect to the main frame 25 and the operating mechanism enclosed thereby.

An endless cutter chain 58 The sprocket B and clutch element 5i are mounted upon a bracket S3 with the ball bearing element 5d intervening. The bracket 63 is shown in Fig. 3 removably attached to theV frame or head 5l As shown in Figs. 2, 3 and 9, the vertical tubular drive shaft 69 is provided with external splines l2 which are engaged by the clutch element '13. 1

The upper side of the clutch element 'i3 is provided With jaws 'i4 adapted to co-operate with the jaws 52 on the underside of the clutch element E i. By means of manually operated mechacan be slid vertically tubular drive shaft 69, to effect a driving connection between the vertical tubular drive shaft 59 and the clutch Ielement El to effect rotation of the driving sprocket Bil of the chain kerf cutter.

Manually operated mechanism for applying or releasing the clutch 'H is shown particularly in Figs. 3 and 9. A shipper comprising Va yoke which nts a circuof the tubular shaft 59, this clutch element will also be rotated and consequently the circular flange 16 will be rotated in the semi-circular groove of the yoke when the chain cutter is being driven by rotation of the sprocket Se.

The yoke 15 is vprovided with trunnions 11, 11 journaled in bearings at the outer ends of the lever arms 18, 18 which are pivoted to the transverse shaft 19 which is carried by a pair of bosses 8B, 3E! screw-threadedly attached to a bottom plate 8| of the cutter bar support or head V51.

It should be understood that the operating mechanism for the clutch 1| must be secured' to the cutter bar support frame ror head so as to move up and down bodily therewith as the kerfcutting unit is adjusted in elevation relative to the main frame 2G as shown in Fig. 2.

A pair of brackets 82, E2 welded to each other, as shown in Fig. 9, are pivotally mounted on the supporting shaft 19, and are connected to stub shafts 83, 83 by means of the transverse pins 84, 84. The rear ends of the arms 18, 18 are pivoted to the stub shafts 83, 83. Removable Cotter pins 85, 85 are provided on the ends of the shaft 1S to maintain the arms 18, 18 in proper relation to the other parts. shown in Fig. 9. By removing the cotter pins 85, 85, the arms 18, 18 may be removed to disassemble the entire shipper mechanism for renewal or repairs.

Extending between the U-shaped arms of the brackets 82, 82 and pivotally mounted with respect thereto is a trunnion 893 which is provided with a central transverse aperture adapted to receive an eccentric extension 81 eccentrically mounted upon a cylinder 83 which is rotatably journaled in the bearing 8? carried by the bottom plate 8|, as shown in Fig. 3. A Cotter pin 90 is provided to maintain the extension S1 in the trunnion 3% and to permit removal thereof. The journal 8S is provided with a pair of laterally extending abutments or stops 9|, 9| which are adapted to limit the throw of a handle 92 which is pivotally attached to the cylinder 8S by -means of a pin 93.

The handle 92 is provided with a cam 9A adapted to co-operate with a spring-pressed plunger 95 which tends to retain the handle Q2 either in the full line position in Fig. 9 or in the dotted line position. When the handle 92 is in its full line position, as illustrated in Fig. 9, it occupies the position shown in Fig. 3. The eccentric extension 81 will then be in its uppermost position. This will rock the arms 1B about the pivot shaft 19 to move the yoke 51 to its lower position to release the clutch 1|. The handle S2 has a movement through a semi-circular path and the limit stops 9| may be in the nature of clips comprising spaced-apart plates of different lengths with a` groove in between for entrance of the lever 92. rIhe pivot 93 may b-e an eccentric and the springpressed plunger 95 may act to hold the arm 92 in either the clip Qi where the yclutch 1| will bev applied, or in the other clip 9| where the clutch will be released. It will thus be seen that the clips. 9i, 9| may be used to positively hold the clutch 1| of Fig. 3 either in its applied position or in its released position.

In order to apply or release the clutch 1| of Fig. 3, the handle 92 of Fig. 9 is first swung about the eccentric pivot 93 which assists in moving the lever 92 away from the clip 9|. When the lever 92 is moved from its full line position to its dotted line position as shown in Fig. 9, the eccentric extension 81 of Fig. 3 will be moved to its lowermost position, thus lifting the yyoke 15 and thereby causing engagement between the jaws 62 and 14 of the clutch elements 6l and 13 of the clutch 1 I. This clutch mechanism 1| therefore provides means for effecting a driving connection between the vertical tubular shaft 69 and the cutter chain 58, but it should be particularly noted that by locating the clutch 1| between the upper end of the tubular shaft 59 and the sprocket liti, the motor 26 may be operated to rotate the haulage rope drum While the cutter chain is not being driven.

As shown in Figs. 2 and 3, the cutter bar support or head 51 carries a depending apron having the shape shown in Figs. 2 and Li and serving as a shield or guard plate for the elevating mechanism hereinafter described, and also as a vertical guard plate overlapping the front end of the main frame, as shown in Fig. 2, in position to abut against the Working face of the mine vein when the kerf cutter is being fed transversely of itself along such mine vein. The apron which is secured to the cutter bar support or head 51 and depends therefrom, as shown in Figs. 2 and 3, comprises a front downwardly extending plat@J S6 and a pair of downwardly extending side plates 91, 91 which are rigidly secured by welding to the i bottom plate 8|. The front plate 96 preferably tapers toward the rear at each side and is provided with a connecting crosspiece 91 at its rear end, as shown in Figs. 1, 2 and 3.

The front plate 96 is provided with hooks 98, 98 on opposite sides of the cutter bar and spaced below the same, as shown in Fig. 2. Also rigidly attached to the bottom plate Si as well as to the front and side plates 96 and 91, on opposite sides of the cutter bar, are attaching brackets 99, 19 each yprovided with a pin it@ adapted to be attached to a coupling member ||l| of the feed cable |02. As will be more fully described herein after, the cable |232 extends from either side of the mining machine to a pulley secured to an anchoiage in the mine distant from the mining machine. The feed rope is reeved around such pulley and its free end brought back for connection either to one of the anchorage hooks 93 or to one of the anchorage pins IBB. When the kerf cutter is in its lowerrnost position and the coal being cut is relatively soft, the free end of the feed rope HB2 may be connected to either of the anchorages 98. But when the kerf cutter occupies its topmost position or when the coal being cutis relatively hard, it becomes necessary to connect the free end of the feed rope closer to the cutter bar or to either of theattaching brackets Sit. The feeding resistance met with by the chain lerf cutter must be balanced against the frictional resistance between the supporting pan and the mine bottom, by so arranging the feed rope db2 in connection with the distant anchorage, and the free end of the rope in proper chine as a whole, with the kerf cutter at adjusted elevation.

As shown in Figs. 2, 3 and 8, the housingfor the gearing of section 23 of the mining machine comprises a removable top part attached to a lower part. The lower part is composed of end walls |93, H34 and'side walls ille, m5. The walls its, vIM andr ||l5 are all rigidly attached to the bottom or skid pan 25, as by welding. The top part of the gearing housing comprises a bottom plate |91, as shown in Fig. 8, welded to end plates il, |09, as shown in Fig. 3, and also welded to side plates I l0, HEB, asy shown in Fig. 6. rThe top part of the gearing section 23 of the mining machine is removably attached to the lower part by means of the bolts |06, |06, as shown in Figs.-2 and 6. The

relation to the mining mabottom of the lower part of the housing is closed by the skid pan plate 25. In fact, the lower part comprising the bottom plate 25, the end walls |03, |64 and the side walls |35, |05, constitutes the skid pan, removably secured by means of the bolts IllS to the upper part of the gear housing 23. The upper part of the housing of the gear seotion 23 is removably secured to the motor section 22 by means of the bolts 24, 24, as shown in Figs. 1 and 4.

The upper part of the housing of the gear section 23 is also provided with a horizontal reinforcing plate I I 8 rigidly secured t0 the side plates I I9 and to the end plate IGS. The horizontal plate II 8 intermediate the bottom plate |01 and the top plate III, shown in Fig. 3, is welded to the vertical tube |20 which extends downwardly and is welded at its lower end to the bottom plate |01 to provide ample space for the elevating mechanism connected between the bottom part of the gear housing and the cutter bar, as shown in Fig. 3. The plate ||8 is also welded to the vertical guide cylinders IIS which form parts of the telescopic guiding mechanism spaced from the elevating device and located between the cutter head 5l and the gear section 23, as shown in Figs. l and 8. The plate I I 3 is provided with a large circular opening for the feeding rope drum I 84, as shown in Fig. 3; but nevertheless, the plate Ii 8 extends over a wide area, as shown in Figs. 4 and 7, to provide support for the mechanism by means of which the feeding rope drum is controlled.

As shown in Fig. 8, the cutter head 51 is provided with laterally extending reinforcing plates i2| which are rigidly secured to the plate 8|, which is the bottom plate of the kerf cutting unit, as shown in Figs. l, 2 and 3.

The kerf cutting elevating mechanism will now be described. Centrally disposed with respect to the cutter head 51 and along a vertical axis which is substantially through the center of gravity of the adjustable kerf cutting unit 2|, I provide a vertical threaded shaft |22 having an upper neck I 23 which is rigidly attached to the cutter bar 56 and the cutter head 51. The vertical shaft |22 is screw-threaded through the upper end of the vertical tubular shaft |24 mounted for rotation in the cup bearing |25 carried by the bottom plate 25. The upper end of the tubular nut shaft |24 is journaled in the cup bearing E26 which may be welded to the top plate shown in Fig. 3.

The upper cup bearing IZI` is provided with a lubrication moat |21 having a lubricating open- 523, as shown in Fig. 3. Lubricating material is supplied to the moat |21 by a downwardly extending tube I 23 carried by the cutter head 51 and co-operating with the grease fitting |30. Lubricating material supplied by the moat |21 will lubricate not only the cup bearing I 26 but also the upper nut portion |3| of the tubular shaft 24, and lubricant may also be expected to seep through the nut |3I and along the screwthreaded shaft I 22 and through the bottom thereof to the cup bearing |25.

The lower end |32 of the tubular shaft |24 is journaled in the cup bearing |25 and provided at its lower end with an annular shoulder to receive the disk plate |34 through an opening in the center of which extends upwardly the hardened bearing pin |33. The lower end of the pin |33 is provided with a circular head, the underside of which may have the shape of a segment of a sphere so as to make point contact with the hardened bearing plate |35 resting in a recess in the bottom of the cup I 25, as shown in Fig. 3. As before stated, lubricant introduced into the moat |21 can by seepage iind its way into the cup |25 to lubricate the pin bearing |33 as well as the cup bearing 25.

Keyed to the lower end portion of the tubular shaft |24 is a sprocket |36 connected by the endless sprocket chain |31 to a sprocket |312 to be driven thereby when the clutch |49 is applied. When the sprocket |36 is rotated, the nut I 3| at the upper end of the tubular shaft I 24 will be rotated, and since the threaded shaft |22 is held against rotation by its rigid attachment to the cutter bar 56 and cutter head 51, rotation of the nut |3| will result in variation in elevation of the kerf cutting unit. 'Ihe nut |3| is rotatable in reverse directions and therefore the kerf cutting unit may be elevated or lowered, as desired.

tical lines when adjusted in elevation, but also to co-operate with the spaced-apart vertical holfeeding strains as the machine is fed by means of the rope feeding mechanism over the mine bottom, particularly when the kerf cutting unit is at relatively high elevation.

The two telescopic guiding mechanisms are substantially the same construction and therefore common reference characters are used for similar elements. Each of said guiding mechacylinder |38, and the transverse pin |43 extends through the bracket and transversely through the cylinder I 38, and the ends of the pi |48 receive to retain the cylinder |38 in posiresist all the feeding strains.

Surrounding each shaft I 38 is a pair of concentric cylinders |42 and |43 each movable upwardly and downwardly relatively to the main The cylinder |43 fits in the cylinder IIS to slide vertically therein, and the cylinder |42 lits in the cylinder |43 to slide vertically therein after the latter has reached the limit of its upward movement. Adjacent the bottoms of the cylinders |42, |43 and |I9 cylindrical recesses provide annular shoulders for engagement by the circular collars or flanges |44, |45 and |45 one after another. It will thus be seen that telescopic guiding devices are provided on opposite sides of the main frame and between the latter and opposite sides of the kerf cutting unit. These screw-threaded lifting device and also entirely separate from the tubular shaft 69. These tubular guiding devices are located at the extreme in the nut |3I; ing devices will consequently resist all the feeding strains during feeding movements. While the guiding de- As shown' in Fig. l, the hand wheel |36 is vices are entirely separate and independent of the located in close proximity tothe motor control lifting mechanism, as shown in Fig. 4, such guidbox 29. While the clutch controlled driving ing devices are in the most efficient position to mechanism forthekerf cutter elevating apparatus prevent feeding strains from being imparted to is entirely enclosed within the main frame, the

Cil

leither the lifting screw mechanism or the tubular clutch |49 may be Operated from Wi'dlOll the f A trunnion nut |132 oo-op'erated with the bracket Diem iS Connected through the vertical tubular t.

tension |66 rigidly attached to the bottom plate In order to assure propel intelllleshillg 0f the drive shaft t9, and consequently while the cutter main frame by rotating the Wheel 1%' lll one bar is rigidly connected to the main frame by direction Or the Other. The clutch idg may thusV means of the two telescopic guiding devices, the be applied or released but thel direction ci elevavertical tubular drive shaft 69 may be most eition of the korf outtlneunt Will depend upon the 10 iiciently rotated without tendency toward binddirection 0f rotation of the electric motor 26 ing even when the korf cutting unit is in its most which may easily be reversed at the motor conm elevated position. Likewise, the lifting mecha- |7101 bOX 29- nism does not tend to bind and may be operated The meChaniSm OI' dfiViIlg the Spliied 'Ullbllat intervals by increments during feed iai Shaft 69 flOn'l thev armatllle Shaft 21 iS 15 when the korf cutting unit 2| is elevated, the shown in Fis. 3. The armature shaft 2l excylinder 13E of each of the guiding devices will tends through an Opening "581D the rear end Wall slide upwardly with respect t0 the Cylinder |42 |09 of the gear section 23. The shaft 21 carries a until its lower flange Md engages the shoulder 0f beveled pinion |69 Which iS keyed to the shaft 21 the cylinder |42. Further upward movement of and is removably held in place bv a out il@ sr, the kerf cutting unit 2| would cause the cylinder on a screw-threaded extension |11 at the inner |112 to be lifted with the cylinder |38 until the end 0f theshaft 21. lower flange |45 engages the shoulder of the In mesh with beveled pinion |59 and mountcylinder |113, whereupon the latter will be lifted. ed for free rotation on the axis of the vertical The limit of the upward sliding movement will be Spiilied tubi-11er driVe'Sharft 59, iS a large dlSh- 25 reached when the circular flange M16 of the cy1- Shaped `IleVel gear |12 provided With a hub porinder ifiS engages the annular shoulder of the tion |13 and a disk portion |13. Secured to the cylinder' |19, the latter being fixed to the main hub portion |13, preferably by welding, is a frame. sleeve or` cylinder |14 splined to the outer side The mechanism for controlling the rotation of of the vertical tubular drive shaft 69. 30 tno vertical tubular shaft |24 of the werf cutting The hub portion |13 of the dish-shaped bevel elevating mechanism, is shown in Fiss. 3 and il. gear |12 is iournaled to the bearing |15 carried Extending upwardly into the splined tubular drive by a downwardly extending cylindrical support shaft te is a vertical shaft itl, the upper end of |16 formed integral with the removable top plate which is feathered to the internal splines of the eS SllOWIl in Fig- 3. The Spliled Sleeve 100i"- 35 tubular drive shaft og 1;@y permit rehrvs rough tion |14 at the center of the dish-shaped bevelv tudinal movement therebetween but to transfer gear |12 iS Splined t0 the vertical drive shaft the rotary movement of the tubular drive shaft S0 as |30 impart rotation thereto" When the motor 59 to the shaft m1 through the keys mg. Beshaft 21 is rotated. The splined connection between the shaft 1M and the drive Chain |31 1 tween the bevel gear |12 and the vertical tubular 1) provide a friction clutch |49 comprising a clutch drive shaft 69 permits the latter to have free verdisk 15g having a. hub |5| keyed to the hws-r end tical axial movement when the kerf cutting unit of the shaft |111. The lower end of the shaft H11 iS adjusted' in eieVaT/OH Thai? iS t0 Say, pf@- is provided with a, hardened bearing pin 53 CO- vision is made for driving the cutter chain 58 operating with a hardened bearing plate 15d set from the' motor Shaft 21 regardless 0f the ele 453 into a recess at the center of a lubricating cup |54 Vated DOSii'liO-U 0f adjustment 0f the kerf Cutting I on top of the bottom plate 25. unit 2| A shiftable clutch elem-ent |55 is provided with A lemOVabie grease Sedi |11 may be provided a, shipper in the form 0f a split ring |55 having at the top of the splined sleeve portion i151 to tmmnons 51) 5g which are journaled in the co-operate with the tubular drive shaft t9. Such 50 arms |53, |58 pivoted to a shaftr |59 mounted upon grease Seal iS located Oli the geel Seeton 23 at bosses 1go, is@ sar-riad by the bottom plate g5, the place where the tubular shaft d@ emerges, as shown in Fig. 1l. The arms |58, |58 are as Si'lOWn in Fig- 2 rigidly attached to a bifurcated split bracket IG It Will thus be Seen that lIiOOl Operated mecha- |51 and with the veri-,109,1 threaded Shaft 93, drive shaft 69 not only to the elevatngvmechaas Shown in pigs. 5 and 11. By rotating the nism but also to the kerf cutting unit. The shaft las, the arms-15a, |53 will loe rotated about .Chain Cutter Should always be driver lo the Same the axis of the shaft |59 to control the applica direction With any gVeYl Setting Ofthe Cll'iei tion or release of the durch |49 bits 59, but when the clutch 11 is released and gq) Rigidly attached to the nuo of the clutch elethe Clutch |49 applied, the electric motor 2e ment |55 is the sprocket |54 which receives` the may Safely be Opedied ill l'eVeTSe dileeiiolfls in drive chain |31. The sprocket |64 is journaled on accordance with the direction of elevation of the bearing |55 carried by the lower tubular ex* the kelf Cutting Unit desiredm1 of the top portion of the housing or gearing bevel gear |12 with the pinion ltd, provide a section 23, as shown in Fig. 3. pair of hold-down rollers |18, |13 as shown in By referring to Fig. 6, it will be seen that the Fie. 4- These rollers |18 engage the upper bevvertical threaded shaft |53 is. mounted between eied Surface 0f t11e geel? i12 Where its Circumthe bottom plate 25 and the removable top plate ference iS at the mlX-imllm- AS SilOWl in Figs. 70 in position to be rotated by the hand wheel 12 and 173. each of the rollers lle '1S supported. bv |86 which is keyed to the upper end of the shaft a stub shaft |19 carried b-y downwardly extending |63 and located outside of the main frame. brackets |85 rigidly secured to the bottom of the Hardened bearing pin and plate means |61 is removable top plate ill. rihe brackets ltd are provided for the lower end of the shaft |63. each split as shown Yin Fig. i3 and provided with 75 a clamping screw |8| to hold the stub shaft |19 in any adjusted position to which it may be adjusted by wrench-receiving sockets |82. The rollers I 18 may be mounted upon the stub shafts |19 by means of ball bearings |83.

For the sake of compactness of operating parts overall length of the main frame at a minimum, I mount the feeding rope drum |88 within the top portion of the housing of the gear section 23, in a position where such rope drum will be concentric with the vertical axis of the tubular drive shaft 69. I also compactly locate planetary gear controlling mechanism within the hollowed out portion of the dishshaped bevel gear |12 and even within the hollowed out portion of the feed drum |84 itself. The planetary gear control mechanism may be operated to effect rotation of the feed rope drum |84 either at a relatively slow feeding speed during kerf cutting operations, or at a relatively high handling speed when the mining machine is to be moved quickly from one place to another.

As shown in Figs. 3 and 4, an eccentric |85 is keyed to the hub |13 of the bevel gear |12. Surrounding the eccentric |85 is a bearing |86 on which is journaled a gear |81. Thegear |81 is connected by welding, as shown in Fig. 3, to a horizontal plate |88 which has a bifurcated extension |89 provided with a slot |90 slidable with respect to a roller |9| carried by a vertical stub shaft |92 secured to a stationary bracket |93 by a pin |94. The bracket |93 is secured by means of the machine screws |95 to the hori- Zontal plate H8, as shown in Fig. 4. Lubricant may be introduced by way of the conduit |96 to the bearing surfaces between the roller |9| and the stub shaft |92, as shown in Fig. 3.

Co-operating with the gearY |81 is a second gear |91 which is mounted upon a hub |98 by being welded thereto, as shown in Fig. 3. The hub |98 is spaced from the hub |13 of the dishshaped bevel gear |12, by journal bearing |99. To the bottom of the hub in Fig. 3, a sun gear 200 concentric with the vertical axis of the tubular shaft 69. The sun gear 200 forms part of a planetary type of transmission as best seen by referring to Fig. 10.

Reverting to the power welded thereto, in Fig. 3. The plate |88 is held against rotation by the roller |9| on the stationary vertical shaft |92 which is rigidly secured to the plate H8. But by reason of the slot |90 co-operating with the roller |9|, the plate |88 Will be free to oscillate as required by the eccentric |85.

The gear |81 has fewer teeth than the gear |91. In the accompanying drawings, the gear |81 has fifty-live teeth and the `gear |91 has fifty-eight teeth. Consequently for each rotation of the dish-shaped bevel gear |12 there will be a complete rotation of the eccentric` |85. If this is in a clockwise direction, the gear |81 will be rotated a slight amount correspondingly. For instance, for each rotation of the eccentric |85, gear |91 will move 15%3 of a rotation, or 3758 of a rotation. Consequently the speed reduction between the gear |12 and the gear |91 will be 58 to 3.

It will of course be obvious that this reduced.

|98 is welded, as shown Y speed will be transmitted from the gear |91 directly to the sun gear 288 through the hub |98. The sun gear 298, as shown in Fig. 10, meshes with the f'our planetary gears 25| which are mounted upon four upstanding shafts 282 carried by a spider 283 mounted upon a cylindrical support 208 which is journaled upon the hub 285 of the feed drum |89, as shown in Fig. 3. |The hub 285 is journaled on the bearing 285 carried by the cylindrical support 281, and the latter in turn welded to the bottom plate |01, as shown in Fig. 3.

Each of the vertical shafts 282 is provided with an upper bearing portion 208 which extends into a journal bearing for a roller 209. An integral annular flange is provided on the shaft 202 at its upper end portion in position to support the roller 289. The rollers 209 are adapted to roll upon the outer surface of the hub |98. A spring-pressed wiping member 2|| is provided adjacent the upper end of said shaft 202 to provide lubrication for the roller 209. Below the annular fianges 2| 8 the vertical shafts 282 each extends through the hub of the brake drum 2|2 which is formed integral with the spider 283. This can readily be seen by referring to Fig. 10 which is Va sectional plan View taken on the line |8, i8 of Fig. 3. A brake band 2|3 provided With a brake lining 2M is associated with the drum 2|2.

' The planetary gears 20| are rotatably mounted with respect to the vertical shafts 282 by double antifriction roller bearings 2|5. Each of said planetary gears 28| is provided with a hub 2|55, to the upper portionrof which the gear 28| is integrally attached, and to the bottom portion of which is attached a planetary gear 2| 1. In other words, as shown in Fig. 3, the hub 2|8 carries both the planetary gear 28| and the planetary gear 2|1, and therefore both gears 20| and 2| 1 always rotate together.

Planetary gears 211 mesh with a ring gear Zit rigidly secured to the interior of the operating drum |85. It will thus be seen that the planetary gear 282 meshes with the sun gear 280, that the planetary gear 25E is connected to the planetary gear 2| 1, and the latter meshes with the gear 2 I8 but is secured to the rope drum |80.

Not only do the planetary gears 285 mesh with the sun gear 288, but also with the ring gear 2| 9 which is integral with the brake drum 228. The brake drum 228 is mounted upon a journal bearing 22| carried on the interior peripheral portion of the rope drum |88. Associated with the brake drum 220 is a brake band 223 provided with a lining 224.

By referring particularly to Fig. 10 of the drawings, it will be seen that the planetary gears 28| have fewer teeth than the planetary gears 2|1, the number of the teeth on each gear 29| being fourteen, and the number of teeth on each gear 2| 1 being sixteen.

As will be described more fully hereinafter, the brake bands 2| 3 and 228 are so interlocked that it will be impossible to clamp both of them at the saine time, and a single operating mechanism is provided whereby when one of said brake mechanisms is applied, the other is released, and vice versa. The brake bands may also be so adjusted that neither will be applied, under which condition power will not be transmitted to the rope drum |82 from the motor shaft 21 but will be free to be rotated by the operator grasping the feed rope and pulling it out from the main caused 16 teeth of each of the planetary gears 2 I 1 to mesh with the ring gear 2 i8, because whenever any planetary gear 20| makes a complete rotation, the planetary gear 2|`| attached thereto will also make a complete rotation, In other 5 Words, While the planetary gear 22| walks around the stationary gear 2|9, the distance represented by 14 teeth, the planetary gear 2li will attempt to walk around the gear 2|9, the distance represented by 16 teeth. The difference of two teeth 10 represents the distance which the rope drum will be rotated during each rotation of the planetary gear 2 That is to say, due to the difference in the number of teeth between the planetary gears 20| and 2|1, it will be necessary for the ring gear 1,-, 2 I8 to rotate in response to the sun gear Walking the planetary gear 20| around the ring gear 2|3 while the latter is being held stationary by the brake 223 being applied to the brake drum 22|).

The planetary gear mechanism shown in Fig. 3, gg controlled by the brakes applied to the brake drums 2 2 and 22), enables the power to be transmitted to the roper drum to rotate the same either at a fast handlingspeed or at a greatly reduced feeding speed. When both brake drums 2|2 and 220 are released by releasing the brakes 2|3 and 223, the rope drum |84 will be free to rotate so that the rope |22 on the rope drum |84 may be pulled out manually from the machine for the rame of the machine and thereby freely rotating 'ne rope drum.

By referring to Fig. 3 of the drawings, it will e seen that if the brake band 213 is applied to `he brake drum 2|2 to hold the same stationary, .he rotation of the sun gear 20|] will be trans- .nitted to the planetary gears 23| and 2 When :he brake drum 2i2 is held stationary, the vern tical shafts 262 will also be held stationary because they are mounted on the brake 2|2 to revolve around the vertical aXis of the tubular shaft S9 only when the brake drum 2|2 is free to rotate.

At the time that the brake 2|3 is applied to the drum 212, the brake 223 is released and therefore the brake 222 is free to rotate. Rotation of the planetary gears 20| about the vertical sta tionary axes of the shafts 202, will be transmitted to the brake drum 222 but this will have no eiect because the brake drum 220 at this timeis free to rotate.

rihe rotation of the planetary gears 2H, however, will effect rotation of the annular gear ZIB which is secured as by welding to the inner side of the large rope drum |82. It will thus be seen that when the brake 223 is released from the brake drum 229 but the brake 2|3 applied to the brake drum 2i2, rotation of the armature shaft 2li will rotate the sun gear 20B, and the planetary gears 2 I1 will be rotated on vertical stationary shafts 222 to eiect rotation of the rope drum |82 on the vertical axis of the tubular drive shaft |59.

planetary gears 2|1, as shown in Fig. 10,

" are somewhat larger than the planetary gears 22 i,

so as to secure a predetermined ratio of the number of teeth on the planetary gears 20| and 2li. In Fig. i0 this ratio is illustrated as being 14 to 16. It will thus be seen that when the sun gear eiects a complete rotation of each of the planetary gears 2m, 14 teeth will be engaged, but 16 teeth of each of the planetary gears 2|`| will be- 'coine effective in their meshing with the internal annular gear 213 which is secured to the inner Wall of the rope drum |84. The transmission of power to the rope drum from the sun gear 22! will therefore be at a relatively fast speed when the brake 2.!3 is applied to the brake drum 2i2 while'the brake drum 223 is released. This rela- -V tit-'ely fast speed of rotation of the drum |22 is useful in handling the mining machine when it is to be moved from one place in the mine to another while the cutting mechanism is not cutting a kerf.

When the brake 2|3 is released and the brake 223 applied to the brake drum 220, a very slow feeding speed of rotation of the drum |82 will be secured. This feeding speed is used when the kerf cutter is cutting a kerf while the machine is j being slid over the mine bottom by the feed rope |32 controlled by the retarding or guide rope 34. When the brake 2|3 is released and the brake 223 applied to the brake drum 22B, the latter together with its inner vannular gear 2|9 Will be held stationary. Since the rope drum 2 |2 is free to rotate, the vertical shafts 202 are free to revolve about the verticalaxis of the tubular drive shaft G9. Rotation of the sungear 22D will cause rotation of thek planetary gears 20| on the vertical bearings 222. Since the brake drum 22|`is held stationary together with its gear 2|9, the planetary gears 20| will Walk around the stationary ring gear 2li?.y

In making a 'complete rotation, the planetary gears 22|, each of which has 14 teeth, will have purpose of connecting it to an anchorage in the 3o mine distant from the machine.

When power is transmitted to the rope drum |84 to rotate the same, a Wide range of speeds of rotation of this rope drum may be obtained by partially applying either of the brakes 2|3 or r,

223 to the brake drums 2i2 and 223, so that slipping may occur between the brake drums and the brake linings 2M and 222. It should be understood, however, that when one brake is applied the other is released.

The mechanism for operating the brake bands 2|3 and 223 so that both may be released at the same time or either applied while the other is released, is shown particularly in Figs. 4, 6 and '7.

The construction for applying one of the brake bands is substantially the reversal of a construction for applying the other brake band. Upon the horizontal supporting plate H2 is secured, by means of machine'screws H3', H3', a casting 326 having a pair of integral brackets 225 and 222. The left-hand bracket 226 as viewed in Fig. 6 is provided with an adjustable stop screw 221 which co-operates with `a spring-pressed lug 228 carried by one end oi' the brake band 2|3, the

other end of which 'carries a lug 222 adapted to be 7 received by spaced abutment means 233 carried by a slide plate 23|. The lug 228 is held against the stop screw 221 by a spring 232 co-operating with the stationary abutment 233 carried by the stationary casting 326. It can readily be seen by referring to Figs. 6 and '.7, that if the slide plate 23| is moved to the left, the brake band 2 i3 will be applied to the brake drum 2 I2, and if the slide 23| is moved to the right, as viewed in Fig. "l, the

brake band 2 i3 will be released. In other words,

when the slide 23| is moved toward the left, the abutment means 232will`engage thev lug 229 to apply the brake band 252 to the brake drum 2l2, While the lug 228 is held by the spring 232 against the adjustable screw stop 221 carried by the stationary bracket 222 which is integral with the casting 326 and the latter secured rigidly to the horizontal supporting plate IIS. y

It should be noted that Fig. 6 is a section taken on the line 6-6 of Fig. 4, looking in the direction screw 234i which corresponds in function to the stop screw 227 but is associated with the mechanism for applying the brake band 223, whereas the stop screw 22? is associated with the mechanism for applying the brake band 2 I3. As shown in dotted lines in Fig. 6, a lug 22S extends from one end of the brake band 223 into a recess between abutment means similar to that designated 23B in Fig. 7. Also as shown in dotted lines in Fig. 6, a spring 232 is associated with a lug 228 and the latter held by the spring 232' against the stop screw 234.

By reason of the reverse arrangement of the Fig. 7 to apply the brake band 2l3 to the brake drum 2l2, but this slide is moved toward the right as viewed in Figs. 6 and 7 to effect the application of the brake band 223 and at the same time release the brake band 2| 3. It will thus be seen that whenever the slide 23| is moved in one direction to apply one brake bandjthe other will be released, and the interlocking is such that both brake bands can not be applied at the same time.

As shown in Fig. 6, a horizontal plate 3l8 secured to the walls Hi?, Il@ is provided to serve as a slide bearing for the slide plate 23|. By means of appropriate bracket plates 235, 235, as shown in Fig. 7, and by overhanging guide bracket 335 integral with the casting 325, the slide plate 23! will be provided with suitable guiding ydevices to maintain the slide plate 23| in a rectilinear, oscillatory path of travel. Oscillatory movement may be imparted to the slide 23| to apply either the brake band 2|3 or the brake 'band 223, by means of a pitman 23S pivotally attached to the slide 23| by means of a keyed pin 237. As shown in Fig. 4, the pitman 236 is pivoted eccentrcally at 238 to a rotary cylinder 239 mounted in appropriate bushings in a cup 26!) rigidly secured to an extension of the casting 326, as shown in Fig. 4. of the cup 249 may be provided with lubricating packing 24|.

Secured to the cylinder 239 intermediate its ends is a worm gear 242 which meshes with a worm 2423 (Fig. 4.) carried by a shaft 264 extending through the adjacent vertical frame plate l lll.

The shaft 244 is journaled in the roller bearings 2135, 2615 carried by the removable tubular support 225. Keyed to the shaft 2M outside of the frame of the machine is an operating handle 241 located adjacent to the horizontal wheel |66 and also adjacent the motor control box 29, as shown in Fig. l.

As may be seen by referring to Fig. l, a single operator standing on the leading side of the machine may have within his reach the wheel |66 unit, the reversing switch lever 3| for controlling the direction of rotation of the motor 26, the conthe motor 26 to the rope drum |84, but the latter will ,be free to be rotated by the manual pulling out of the rope |92. Upon rotating the hand Wheel 241 in one direction, the rope drum will be rotated at a fast or handling speed when the machine is to be moved about the mine from place to place. During handling operations the rope |02 becomes a haulage rope and may be extended around the vertical rollers 38 and 39 and thence reeved through the pulley 33 so that when the free end of the rope |02 is connected to an anchorage in the mine and the rope drum |84 operated by the motor 26, the whole machine may be slid over the mine bottom rearwardly and longitudinally.

It should also be understood that the rope |02 may be connected to the rope drum E82 and mounted thereon in either direction, depending upon the direction of feeding movement of the mining machine. When the feed is opposite to that shown in Fig. l, the cutter bits 59 should be reversed and the guide rope 32 extended in lan opposite direction to an anchorage in the mine.

Not only have I completely enclosed yall of the operating parts shown in Fig. 3 within the housing of the main frame, except for the openings 248 and 229 for the rope m2, but I have also employing a rop-e drum of relatively large diameter which has the advantage of prolonging the life of the feed rope @2 by reducing to a minimum the necessary bending thereof. The pull on the guide rope Sd is relatively small but the pull on the feed rope M32 during coal cutting operations is relatively very large and consequently it is desirable to use a very strong feed rope |02 and prolong its life by reducing to a minimum the necessary bending thereof.

The openings 248'and 2fl9 shown in Fig. 2 may be provided on both sides of the machine, and likewise a guide pulley 25| may be provided on that side of the machine opposite to the guide pulley 25D. L Y

When the cutter bits 59 are arranged as shown in Fig. l, and the feed and guide ropes |02 and Viewed in plan. While the brake 223 is `applied and the brake 2li released, the sun gear 200 will transmit to the rope drum |84 a slow feeding speed.

partially applied clutch or brake elements Il?, 49 as controlled by the wheel 52. To reduce the overall length of the main body of the machine tached from the rear side of the motor section 2 by removal of the cotter pin 253 shown in Fig. 5. f

to the machine, in securing the desired balanced pulls on the lower and upper portions of the mining machine structure considered as a whole.

When sumping operations are to be performed in the working face adjacent to the rib, the feed rope |02 is disconnected from its anchorage |00 shown in Fig. 1, and the rope |92 is reeved around the rollers 38, 39, pulley 33, roller 36, and pulley 25|, and the free end of the rope m2 connected to an anchorage between the cutter bar and the rib. The retarding rope 34 is then preferably extended from that side of the machine opposite to that shown in Fig. 1 and connected to such anchorage in the mine near the rear end of the machine as to enable the controlling mechanism shown in Fig. 5 to cause such retardation of the rope drum 4d as to co-operate with the sumping of the kerf cutter into the coal face, first at an angle to the rib and then parallel thereto when the sumping cut is completed. After such sumping cut has been made, the connections of the ropes |02 and 34 may be restored to the position shown in Fig. 1, whereupon thev feed of the kerf cutter may continue from the sumping cut in the direction of the arrow 252. A lateral extension 338 from the lower bracket 339 (Fig. l) may be used to prevent the feed rope |02 from running off the roller 35.

It should be particularly noted that the dishshaped support |13 for the large bevel gear |12 not only provides ample space for the planetary gear brake mechanism beneath and within the same, but also eliminates additional gearing meshing with the bevel pinion'v E69 while the shaft 21 is maintained in a relatively low position so that the bottom of the motor section 22 may make direct sliding contact with the mine bottom while rigidly connected to the gear section 23, as shown in Fig. 2.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scoperof the invention as defined by the claims hereto appended, and I therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an, embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

1. In a mining machine, the combination with a supporting frame, of cutting mechanism mounted thereon for adjustment in elevation relative thereto, guide means connected between said frame and said cutting mechanism and comprising a cylinder rigidly connected to said frame with a cylindrical enlargement at-its lower end to form an annular abutment intermediate its ends7 a floating hollow cylinder within said first-named cylinder and having at its lower end an annular outwardly projecting flange adapted to slide along said cylindrical enlargement and abut against said annular abutment to limit the upward movement of said floating cylinder, a cylinder connected to said cutting mechanism to move up and down therewith, means connecting said last-named cylinder to said floating cylinder to effect lifting of the latter after the cutting mechanism has been lifted a predetermined distance from its lowermost position, means for elevating said cutting mechanism with respect to said frame, and means for operating said cutting mechanism in its adjusted position.

2. In a mining machine, the combination with a supporting frame, of cutting mechanism mounted on said frame for adjustment in elevation relative thereto, motor-operated mechanism comprising a vertically extensible shaft co-nnected to said cutting mechanism to drive the latter, a vertical non-rotatable screw fixed to the cutting mechanism and depending therefrom, cup bearings at the top and bottom of said frame, a nut threaded on said non-rotatable screw and journaled in the cup bearing at the top of said frame, a downwardly extending tubular extension from said nut journaled at its lower end in the cup bearing at the bottom of said frame, meansv comprising sprocket chain gearing connecting said shaft and said tubular extension for rotating said nut and extension in said cup bearings to effect variation in elevation of said cutting mechanism, and means for effecting feed of said cutting mechanism.

3. In a miningmachine, the combination with a supporting frame, of cutting vmechanism mounted thereon for adjustment in elevation relative thereto, power-transmission mechanism comprising a hollow shaft connected to said cutting mechanism to move up anddown bodily therewith and splined exteriorly to a driving gear mounted on said frame, elevating means for the cutting mechanism, and power-operated mechanism for operating said elevating means and comprising a driven shaft mounted on said frame in fixed relation thereto and splined to the interior of said hollow shaft to rotate therewith while the hollow shaft is in its various elevated positions.

4. In a mining machine, the combination with a supporting frame adapted to rest on and slide over a mine floor, of kerf-cutting mechanism mounted thereon for adjustment in elevation relative thereto, means for effecting such adjustment in elevation, an apron depending from said korf-cutting mechanism in overlapping relation to the forward end of said frame and movable bodily up and down with said kerf-cutting mechanism, motor-operated means for driving said kerf-cutting mechanism, an anchorage on said apron and spaced below said cutting mechanism, and mechanism comprising a flexible draft element with its free end adapted to be connected to said anchorage to slide said frame over the mine door and thereby secure feeding movement-of said kerf-cutting mechanism.

5. In a mining machine, the combination with a base frame adapted to rest on and slide over a mine floor, of a supplemental frame mounted thereon for adjustment in elevation relative thereto, a downwardly extending plate extension at the forward end of said supplemental frame in position to overlap the front end of said base frame, a kerf-cutter comprising a cutter bar mounted on said supplemental frame to move bodily up and down therewith, means for elevating said supplemental frame together with said kerf-cutter, motor-operated means for driving said kerf-cutter at the elevation to which adjusted, anchorages on said frame and extension one of said anchorages being approximately in the plane of the cutter bar and another anchorage spaced below such plane, and means compricing a flexible draft element the free end of which is adapted to be connected to either of said anchorages in accordance with the elevation of the cutter bar to secure feeding movement of the kerf-cutter.

6. In a mining machine, the combination with a main frame, of a motor carried thereby, a vertically adjustable supplemental frame, a kerfcutter carried by said supplemental frame and movable vertically therewith, means for elevatgroup of splines for driving said elevating means from said upright shaft.

7. In a mining machine, the combination with a supporting frame, of cutting mechanism mounted thereon for adjustment relative thereto, extensible guiding mechanism comprising a tubular guide connected rigidly to said frame and telemove bodily therewith, each of said tubular guide members having an inner enlargement at one end portion to form an endless -abutment intermediate its ends, said the first-mentioned each successively extend the telescoping guiding members, and means for operating said cutting mechanism in its adjusted position.

8. In a mining machine, the combination with a supporting frame, of a kerf cutting unit comprising a kerf cutter mounted on said frame for adjustment in elevation relative thereto, a vercutter by rotation of said rst-nam-ed shaft.

In a mining machine, the combination with a main frame, of a supplemental frame mounted thereon for adjustment in elevation relative thereto, a motor on said main frame, cutting 10. In a mining machine, the combination With ortable frame, of a support mounted above said kerf-cutting mechanism at the rear end of the eiTective length of the latter, said apron being mounted in overlapping relation to the forward coal face during kerf-cutting operations of the machine.

11. In a mining machine, the combination with a base frame adapted to rest on and slide over a thereto, a horizontal chain kerf-cutter comprising a horizontal cutter bar rigidly connected to said supplemental frame to move bodily therewith, power-transmission mechanism extending from said base frame to said chain kerf-cutter to drive the same, means for adjusting the elevation to said chain kerf-cutter to drive the same, means frame relative to said base frame to vary the elevation of the kerf-cutter relative to the mine bottom, an apron` rigidly connected to said supmeans for feeding the kerf-cutter by sliding said base frame over the mine bottom While said front vertical face is adapted to aio-ut the Working face of the mine vein and slide along the same.

LEWIS E. MITCHELL.

in elevation relative', 

